Plasma Waste Disposal

There is a great and scorching problem in contemporary, fast growing society, namely creation of huge amount of noxious refuse, called municipal waste, which is more and more dangerous to natural environment that we belong to.

Four categories of Municipal Waste

Type of waste

Annual amount of trash per person [kg]

Typical waste constituents

Conventional utilization methods

Municipal

550

All sorts of domestic refuse such as paper, plastics, metals, chemical compounds, and organic compounds, etc.

▪ Storage on landfills

▪ Simple incineration and production of by products such as ash, trash remnants, and some energy

The Problem

Conventional waste utilisation methods certainly do not solve problems, because the harmful residues such as ash, dust, gases left behind can not be filtered off even with the usage of innovative technologies. Municipal waste problem is undoubtedly waiting for proper solutions. Many meetings are held in the Ontario’s municipal offices, numerous articles recently appeared in press, all of them discussing this growing concern.

Protests from local communities, who live in the vicinity of landfills and incineration sites decorate columns of our newspapers, because their safety and well-being is constantly in danger.

Future municipal contracts for shipping refuse to Michigan will cease by 2010. What will happen when the border closes? The reasonable assumption is that even after we divert, compost, recycle, reuse and implement all the current waste diversion methods, Toronto will be stuck with 30–40 per cent of the waste. This includes 15 million chip bags, 10 million light bulbs, 5 million toothbrushes and 100 000 mattresses that Toronto sends to landfills each year (Toronto Star, Royson Jame).

The Solution

We, the authors of this article, would like to present most favourable solution to this conundrum. The solution is a modern and clean technology of plasma utilization to incinerate all kinds of trash.

Plasma technology is known for more than a half of century and was developed and used particularly in metallurgy for production of high-grade steel. Today, it is widely used for municipal waste utilization. In Japan two converters are working already and transform 200 tons per day. Plasma technology is currently being developed in Italy, Spain and other European countries. In North America there are companies, which produce plasma converters that have mobile and stationary capabilities.

In Canada this technology only begins to claw and all initiatives in this direction are not seen with enthusiasm. Therefore, the goal of this article is to prompt Ontario’s government, the municipal authorities and people who are responsible for the utilization of municipal waste in Ontario and Canada to take the action.

What is plasma technology?

Very hot plasma is formed by ionized gas (i.e. Oxygen, under normal pressure) in the strong electrical arc with the power ranging from 2 to 20 Mega Watts. Temperature of such plasma is very high, ranging from 2 to 6 thousand degrees Celsius. In such high temperature all waste constituents, including metals, toxic materials, silicon, etc. are totally melted forming non–toxic dross. Plastic, biological and chemical compounds, toxic gases yield complete dissociation (required minimal dissociation temperature is in the range of 1500 degrees Celsius) into simpler gases mainly H2 and CO2. Simpler gases, mainly H2 can be used as ecological fuel to generate heat energy and electrical energy decreasing significantly (even to zero) cost of plasma formation and waste utilization. Regained metals from dissociation process can safely return to metallurgic industry, and slag can be used as an additive to road and construction materials.

The utilization of municipal waste using this method does not cause the emission of foul odours and does not produce a harmful ash, which is something that normally takes place in an incinerating plant.

Fig.1. Plasma dissociation of toxic organic gases in temperatures ranging 3000 to 6000 degrees Celsius. Required minimal dissociation temperature of organic molecules is in the range of 1500 degrees Celsius, which is close to melting temperature of metals.

What are the main advantages of plasma technology?

Plasma method utilizes efficiently all four types of hazardous, toxic or lethal waste because of high temperature, capable of disassociating molecular bonds.

Plasma waste utilization method takes place in a close system, without releasing ashes, waste remnants, dusts and toxic gases into environment. Regained metals return to metallurgic industry and created slag is used as an additive to road construction materials. Non-toxic gases, which are created, are stored in special containers (gas cylinders) and used as fuel and energy creators.

The volumetric waste reduction for most solid wastes is approximately 300 to 1. Conventional incineration ratio is in the range of 5 to 1 since large quantities of ash are produced.

Plasma technology allows converting large quantities of municipal waste in the range of 10 to 500 tons a day.

This method of waste reduction is the only method available to reduce electronic waste, which does not undergo biodegradation.

The costs of using plasma technology are significantly reduced from $40/ton to ZERO as a result of creation of ecologic by-products. The costs of using conventional incineration are in the range of $100/ton.

Contaminates in slag and gases created during plasma utilization with elements such as mercury, cadmium, sulphur, SO2, HCL, dioxins, selenium, chromium, lead, barium, arsenic, radioactive elements are strictly controlled by usage of special water or dry scrubbers and filters. Using this method elements are considerably minimized below environmental standards. The remainder of the pollutants sink into glassy slag and can be treated further in close system, which is a major distinction to conventional incineration.

The ashes that are formed as a result of conventional incineration can be burned down to further using plasma technology to make them harmless.

Contemporary plasma converters are computer controlled, safe, quiet and can be stationary or mobile.

Plasma waste utilization will improve public health and safely achieve “total and irreversible destruction of hazardous and toxic compounds”, “lethal viruses, bacteria and prions that are so dangerous to our health.” (Startech Environmental Corp.)

We must act now

With this article, we would like to popularize the usage of plasma arc gasification
and vitrification technology for waste disposal. We would like to encourage investors to open up to this technology, and municipal government to direct waste disposal stream to us so we can show benefits. No one should be afraid of this technology, on the contrary, due to its advantages this technology should be implemented as soon as possible to preserve the clean environment on our planet and the health of its inhabitants.